Combined Effects of Temperature and Salinity on Larval Development of the Mangrove Crab <i>Parasesarma catenata</i> Ortman, 1897 (Brachyura: Sesarmidae)

Abstract

Abstract-The larval stages of the mangrove crab Parasesarma catenata were reared in the laboratory from eggs of females collected in the Mgazana estuary, South Africa. Survival and duration of larval stages were tested for the combined effects of temperature and salinity in a factorial design experiment, using three females each with two replicates of 15 larvae per combination. Combinations were made from five temperature (15, 20, 25, 30 and 35 ºC) and four salinity values (15, 25, 35 and 45 ‰). Results were tested by ANOVA and multiple regression was applied to generate contour models by polynomial equation. It was found that P. catenata larvae develop optimally in near to seawater salinity at a temperature of around 25 ºC. These results support the assumption that newly-hatched larvae of this species are exported from the estuarine environment to the sea for development.

Status of the population structure of the mangrove crab Ucides cordatus (Decapoda: Ocypodidae) on the Piraquê-açu River estuary, Espírito Santo, Brazil

“…The dominance of juveniles on the upper estuary could be related to the presence of predators such as fish and paddle crabs on the lower and middle estuary (WILSON, 1989;ALVES and NISHIDA, 2002;DANKWA andGORDON, 2002 andKRUMME, 2004), while the upper estuary crabs are less vulnerable to predation. Upper estuarine areas are inundated only during spring tides and remain under water for a shorter time, thus reducing predation risk (GÓES, 2003;PAULA et al, 2003 andKRUMME, 2004). These juveniles can walk down the estuary as they grow older, and enjoy a greater competitive advantage for more suitable locations near riverine areas, with preferred food (leaves of R. mangle), soft sediment which facilitates burrowing (NORDHAUS et al, 2006) and proximity to water for spawning.…”

Hot and salty: the temperature and salinity preferences of a temperate estuarine shrimp larva, Upogebia pusilla (Decapoda: Thalassinidea)

“…Larvae had a higher tolerance to temperature changes (optimal temperature ranging from 23 to 28°C) than to salinity fluctuations (optimal salinity around 35). Estuarine species that have a narrow tolerance range and reach optimal development near seawater salinity generally present a larval exportation strategy, with newly hatched larvae migrating rapidly to neritic areas, thus avoiding the changing estuarine environment at an early stage (e.g., Nagaraj, 1992Nagaraj, , 1993Paula et al, 2001Paula et al, , 2003. Maximum survival of U. pusilla larvae at salinity 35 clearly suggests a larval exportation strategy for this species, which is supported by the presence of zoea I in the terminal section of the estuary (Paula, 1993).…”

“…Although some species may have a wide tolerance range and present larval retention inside the estuary (e.g. Antonopoulou & Emson, 1989;Paula, 1993;Munro et al, 1994;Numaguchi, 1998;Verween et al, 2007), many species have to avoid the changing estuarine environment at an early stage by exporting the newly hatched larvae to neritic areas, undergoing most development in seawater and returning to the estuary at the less vulnerable megalopal stage (e.g., Nagaraj, 1992Nagaraj, , 1993Paula et al, 2001Paula et al, , 2003.…”

Settlement patterns of two sesarmid megalopae in the Sai River Estuary, Ishikawa Prefecture, Japan

“…Megalopa samples collected from the river were identified based on DNA sequencing. Sesarmid crab megalopae have been reported to return to areas near their adult habitats (Paula et al 2003, Cannicci et al 2019. Therefore, we also investigated the distribution of the adults of each species within the land area adjacent to the river during their active period, based on the hypothesis that megalopa larvae will return to an environment dominated by adults of the same species.…”